Mechanical pencil

Abstract

A mechanical pencil having a rotational drive mechanism which gradually rotates a writing lead on application of writing pressure and allowing rotational operation of the writing lead to be known reliably. First and second cam faces 6 a and 6 b are respectively formed at one end face and the other end face of a rotor 6 in an axial direction, and first and second fixed cam faces 13 a and 14 a arranged on the body cylinder side so as to respectively face the first and the second cam faces are provided to form the rotational drive mechanism for the writing lead. A plurality of grooves 8 a in the axial direction are formed at a slider 8 of a pipe end 7 which projects forwardly from a body cylinder 1 . Therefore, the user can see the grooves 8 a (provided for the slider 8 ) rotated by rotation of the rotor 6.

The invention claimed is: 
     
       1. A mechanical pencil arranged to grasp and release a writing lead by reciprocation of a chuck provided in a body cylinder so as to inch said writing lead forward, having a rotational drive mechanism for rotationally driving a rotor in one direction in conjunction with retreat operation of the writing lead into the body cylinder by the writing pressure applied to said writing lead and forward movement of the writing lead from the body cylinder by releasing the writing pressure, and arranged to transmit rotational motion of said rotor to said writing lead,
 wherein a component arranged to extend from said body cylinder forwardly or rearwardly of said body cylinder is arranged to be rotationally driven in conjunction with the rotational motion of said rotor, and said component is provided with a display means for displaying a rotation state of said component. 
 
     
     
       2. A mechanical pencil as claimed in  claim 1 , wherein said display means is printing or a coating provided on said component. 
     
     
       3. A mechanical pencil as claimed in  claim 2 , wherein said component arranged to extend from the body cylinder forwardly of said body cylinder is a slider for supporting a pipe end. 
     
     
       4. A mechanical pencil as claimed in any one of  claim 2 , wherein said component arranged to extend from the body cylinder rearwardly of said body cylinder is a knock cover which achieves the reciprocation of said chuck. 
     
     
       5. A mechanical pencil as claimed in  claim 1 , wherein said display means is arranged by forming a cross-sectional shape perpendicular to an axial direction into a particular shape different from a true circle. 
     
     
       6. A mechanical pencil as claimed in  claim 5 , wherein grooves are formed on a surface of said component in an axial direction. 
     
     
       7. A mechanical pencil as claimed in  claim 6 , wherein said component arranged to extend from the body cylinder forwardly of said body cylinder is a slider for supporting a pipe end. 
     
     
       8. A mechanical pencil as claimed in any one of  claim 6 , wherein said component arranged to extend from the body cylinder rearwardly of said body cylinder is a knock cover which achieves the reciprocation of said chuck. 
     
     
       9. A mechanical pencil as claimed in  claim 5 , wherein said component arranged to extend from the body cylinder forwardly of said body cylinder is a slider for supporting a pipe end. 
     
     
       10. A mechanical pencil as claimed in any one of  claim 5 , wherein said component arranged to extend from the body cylinder rearwardly of said body cylinder is a knock cover which achieves the reciprocation of said chuck. 
     
     
       11. A mechanical pencil as claimed in  claim 1 , wherein said component arranged to extend from the body cylinder forwardly of said body cylinder is a slider for supporting a pipe end. 
     
     
       12. A mechanical pencil as claimed in any one of  claim 1 , wherein said component arranged to extend from the body cylinder rearwardly of said body cylinder is a knock cover which achieves the reciprocation of said chuck.